The National Theatre unveils its new temporary theatre space, designed by architects Haworth Tompkins.

London’s Southbank has been given an injection of colour, thanks to the National Theatre’s new temporary theatre space. The Shed, designed by architects Haworth Tompkins and built in just under a year, is a striking, exciting structure, which heralds the start of a multi-million pound redesign of one of Britain's most iconic cultural institutions.

It is large, red and angular. Four chimneys shoot up from each corner of the timber-clad building, puncturing its grey surroundings, playfully willing you to explore inside. It couldn’t be more dissimilar to The National, whose concrete structure represents a history of British theatre that can seem exclusive. “We wanted The Shed to feel welcoming,” says Steve Tompkins, co-partner of architects Haworth Tompkins. “I love the main building but I’m realistic about its flaws. At the time it was designed, there was nothing to look at on the South Bank, there was no river walk. So as a consequence it’s quite impenetrable from the outside.” Erected in-part to tackle this issue, The Shed will temporarily replace the Cottesloe theatre, which has been demolished as part of the £70million redevelopment programme affecting a huge proportion of the National Theatre. Focusing on re-energising the theatre, The Shed offers the National a chance to experiment with new forms of theatre.

Like the Cottesloe, it is a small studio theatre, seating up to 250 people. Currently set up in a thrust stage format for Tanya Ronder’s play Table - running from 9 April to 18 May - it is an intimate and flexible space, in which two tiers of black seats sit so close to the stage that it will be nigh on impossible for performers to ignore them. “The Shed emboldens the managing team and artists to take risks,” Tompkins adds. “It’s a bit dangerous, a bit edgy. But it’s still accessible.”

While from the outside the building may seem to perch, playfully, teasingly on the edge of its parent theatre, you can only access the space by going through the main building – the two are seamlessly joined. Once inside, it doesn’t feel tacked on. Rather, it works with the original structure, enhancing and exciting the theatre’s ground floor foyers.

The Shed is made almost entirely out from rudimentary materials such as steel, plastic and timber. And Tompkins doesn’t try to disguise them. A long wooden bar stands to the right of the entrance to the space, and wooden benches, tables and stools are scattered around the foyer. It's reminiscent of the Underbelly venue at the Edinburgh Fringe Festival – rugged, but ready to be used and enjoyed.

“We don’t want people to feel manipulated,” says Tompkins. “That’s the worst thing you can you do as an architect. There is a whole generation of people who are positively allergic to being manipulated by design. So there’s an aesthetic of under-designed architecture. Obviously you can’t create something like this without designing it, but you can do it in an open-ended way where people feel comfortable to be themselves.” In this sense, they have triumphed. Almost all of the solid walls are covered with black chalk boards. Instead of plasticated signs, information has been scrawled on walls and doors in white chalk. Casual and unassuming, the interior of The Shed juxtaposes wonderfully with its loud exterior.

The Shed will remain in place until February next year, by which time the Cottesloe will have been renovated, ready to reopen as the Dorfman theatre. In the mean time, it offers the National ample opportunity to experiment with an exciting programme befitting this unique setting.